1. Field
A positive active material and a method of preparing the same, and a rechargeable lithium battery including the positive active material are disclosed.
2. Description of the Related Art
Batteries transform chemical energy generated from an electrochemical redox reaction of a chemical material in the battery into electrical energy. Such batteries are divided into a primary battery, which should be disposed of after the energy of the battery is all consumed, and a rechargeable battery, which can be recharged many times. The rechargeable battery can be charged/discharged many times based on the reversible transformation between chemical energy and electrical energy.
Recent developments in high-tech electronics have allowed electronic devices to become small and light in weight, which leads to an increase in portable electronic devices. As a power source for such portable electronic devices, the demands for batteries with high energy density are increasing and research on rechargeable lithium battery is briskly under progress.
The rechargeable lithium battery is fabricated by injecting electrolyte into a battery cell, which includes a positive electrode including a positive active material capable of intercalating/deintercalating lithium ions and a negative electrode including a negative active material capable of intercalating/deintercalating lithium ions.
Meanwhile, when the rechargeable lithium battery is charged and discharged, a passivation film called a solid electrolyte interface (SEI) may be excessively formed on the surface of the electrode through a reduction reaction of an electrolyte solution. The excessively formed passivation film hinders transfer of lithium ions and thus the performance of the rechargeable lithium battery may be deteriorated by the excessively formed passivation film.